Supported ruthenium in which a ruthenium component, such as a ruthenium compound and metallic ruthenium, is supported on a carrier is preferably used as a catalyst in production of chlorine, due to its high catalytic activity on oxidation of hydrogen chloride with oxygen (see, for example, EP0743277A1, U.S. Pat. No. 5,908,607, EP936184A2 and US2002/0028173). However, since the ruthenium compound as a raw material is expensive and also its catalytic activity is gradually deteriorated by sintering of the ruthenium component and the like during its use, to finally result in necessity of its exchange, reduction in catalyst cost in production of chlorine using supported ruthenium as a catalyst becomes an important problem.
As one solution for reducing the catalyst cost, by improving durability of catalytic activity (i.e., catalyst life) of supported ruthenium, extension of period of from start of use of the catalyst to its exchange is exemplified. For example, JP-A-2002-79093 (WO2001/010550) proposes improvement of catalyst life of supported ruthenium oxide by using, as a carrier, titanium oxide calcined at 550° C. or more and having a rutile crystal structure. Moreover, JP-A-2004-181408 proposes improvement of catalyst life of supported ruthenium oxide by controlling the specific surface area of the supported ruthenium oxide to from 13 to 16 m2/g.